Warning: this open statement shadows the module identifier Foo (which is later used)

[kevinsimper]

What should I do here? Creating this issue because there is no good resources anywhere about this if you are a beginner to reasonml.

I do a lot of Node.js and the biggest for thing for me to get with reasonml is how to split up your app between files like you would do with require(). I have looked at the generated output and understand that.

Found this link https://stackoverflow.com/a/26824143/804984

You can remove the warning by doing open! .. but the docs does not say anything about it.

School.re

module School = {
  type profession = Teacher | Director;

  let person1 = Teacher;
  let getProfession = (person) =>
    switch person {
    | Teacher => "A teacher"
    | Director => "A director"
    };
};

demo.re

open School;
let anotherPerson: School.profession = School.Teacher;
print_endline(School.getProfession(anotherPerson));

[strega-nil]

@kevinsimper open X; makes all of the things in X available without the module specifier in your current module; something like this:

open School;
let anotherPerson: profession = Teacher;
print_endline(getProfession(anotherPerson));

If you don't want to do that, you can always just write

let anotherPerson: School.profession = School.Teacher;
print_endline(School.getProfession(anotherPerson));

without the open :)

[chenglou]

@kevinsimper open is discouraged from the docs of your snippet precisely because of these reasons. However, we can provide a better help here. Do you have an example snippet where this warning triggers?

[kevinsimper]

@ubsan @chenglou thank you for your responses, I did try to remove Open, but then I get this error in the default bs-platform tool:

let anotherPerson: School.profession = School.Teacher;
print_endline(School.getProfession(anotherPerson));

$ npm start

> my-first-app@0.1.0 start /Users/kevinsimper/Projects/test/my-first-app
> bsb -make-world -w

Package not found: resolving package School in /
File "bsconfig.json", line 1
Error: package School not found or built , if it is not built
Please run 'bsb -make-world', otherwise please install it
>>>> Start compiling
Rebuilding since just get started
Package not found: resolving package School in /
File "bsconfig.json", line 1
Error: package School not found or built , if it is not built
Please run 'bsb -make-world', otherwise please install it
>>>> Finish compiling(exit: 2)

[chenglou]

Your configuration is wrong. What's your bsconfig.json like? There shouldn't be any mention of school in it

[kevinsimper]

@chenglou sorry, that was a attempt to make it work, here is without, I would love to know what I do wrong, then I can help with the docs for newcomers that has the same troubles as I have

https://github.com/kevinsimper/my-first-reasonml

$ npm start

> my-first-app@0.1.0 start /Users/kevinsimper/Projects/test/my-first-app
> bsb -make-world -w

>>>> Start compiling
Rebuilding since just get started
ninja: Entering directory `lib/bs'
[1/1] Building src/demo-MyFirstApp.cmj
FAILED: src/demo-MyFirstApp.cmj /Users/kevinsimper/Projects/test/my-first-app/src/demo.bs.js src/demo-MyFirstApp.cmi
/Users/kevinsimper/.nvm/versions/node/v9.1.0/lib/node_modules/bs-platform/lib/bsc.exe -bs-package-map my-first-app  -bs-package-output commonjs:src -bs-assume-no-mli -bs-no-builtin-ppx-ml -bs-no-implicit-include  -I . -I src  -w -30-40+6+7+27+32..39+44+45+101 -bs-suffix -nostdlib -I '/Users/kevinsimper/Projects/test/my-first-app/node_modules/bs-platform/lib/ocaml' -no-alias-deps -color always -bs-re-out -bs-super-errors -o src/demo-MyFirstApp.cmj -c  src/demo.mlast

  We've found a bug for you!
  /Users/kevinsimper/Projects/test/my-first-app/src/demo.re 1:20-36

  1 │ let anotherPerson: School.profession = School.Teacher;
  2 │ print_endline(School.getProfession(anotherPerson));

  This type constructor's parameter, `School.profession`, can't be found. Is it a typo?

ninja: build stopped: subcommand failed.
>>>> Finish compiling(exit: 1)

[kevinsimper]

I got help from @cem2ran, it was because a file itself declares a module, so you don't need to declare it inside the file as well. I did not understand that from this page, https://reasonml.github.io/guide/language/module

To improve this, would it make sense to make another page about file structure and modules? And adding something here about the equivalent of node.js module.exports and exports?

[anmonteiro]

Doesn’t seem like a bug